1. Field of the Invention
The present invention relates to a device for supplying air to a double-surface-aerodynamic-profile, and typically a paraglider or a parachute. More specifically, the device according to the invention is intended to permit the supply of air to the space situated between the lower surface and the upper surface of a parachute or of a paraglider.
2. Description of the Prior Art
Traditionally, this air supply is effected by an open space, provided at the front of the paraglider, and typically representing between 1 and 20% of the total surface area of the lower surface. This air supply between lower surface and upper surface is intended to permit the advance of the paraglider or of the parachute in a plane other than the purely vertical plane of the to gravity.
Paragliders are currently known which possess at the location of their forward zone, an a-jour fabric of "mosquito net" type, but the ventilation aperture surface area of which never exceeds 20% of the total surface area of the lower surface. Now, this supply zone exhibits a surface area which is insufficient under certain flight conditions. Moreover, this zone is partially or entirely blocked when the whole or part of the front of the appliance, i.e. paraglider or parachute, becomes folded, for example on account of aerological turbulences. Moreover, this forward zone is in some instances poorly ventilated along the direction which is adopted by the appliance, and the aerodynamic profile of the paraglider is then no longer ensured correctly, leading in certain instances to a significant fall of the appliance.
In the document EP-A-0,336,277, a paraglider has been proposed, the lower surface of which is equipped with a flap valve which is liable to give rise to pressure variations at the location of the space situated between the lower surface and the upper surface. Nevertheless, this system incorporating a flap valve does not permit the maintenance of a correct aerodynamic profile of the appliance. In fact, it generates at the location of the sail of the paraglider local variations of pressure which are unsuited to slight, as these may give rise to the folding of the sail. Moreover, when using such a system it has been possible to observe phenomena of autorotation, generally leading to the falling of the appliance.